For those curious about the performance changes for Intel Sandy Bridge hardware when moving from Ubuntu 11.10 to Ubuntu 12.04, here is a quick overview.
This performance testing shows results from an Intel Core i5 "Sandy Bridge" system when running the stock Ubuntu 12.04, the stock Ubuntu 12.04, and then an updated Ubuntu 12.04 setup using the Git components for several critical pieces to the Linux stack.
These updated components include the Linux 3.4 development kernel, xf86-video-intel 2.19+, Mesa 8.1-devel, and GCC 4.8.0 20120429. Ubuntu 11.10/12.04 were left with their stock system settings and flags/options. The tests in this article are primarily looking at the Sandy Bridge graphics performance as well as the all around processor performance for this now generation-old Intel hardware. More Intel Ivy Bridge benchmarks from Ubuntu 12.04 are in the publishing queue.